Homebrew SWR and power meter


Flathagen blogged about his DIY SWR meter project:

The circuit is based on two AD8307 log amplifiers, which are connected to the forward and reflected ports on a directional coupler. The AD8307 amplifiers gives a DC voltage of about 25mV/dB of the input signal, which is amplified using an opamp (LM324). The opamp also provides the reference voltage to the Arduino (AREF) to ensure that the full ranges of the A/D converters are used.
I used the fourth opamp in the quad LM324 to provide input voltage reading. That is why the PCB in the picture has two power jacks. One input and one output. That way I know the drive voltage for the radio. I primary plan to use this device for my Softrock.

Project info at Flathagen DIYycrap blog.

Join the Conversation

1 Comment

  1. very interested in your project. could you send your circuit diagram to me ..
    i woutld like to build one for 100 watts to 1000 watts
    please include the code for it if possable.

    thanks douglas

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.